Jacob Greaves’ delightful first-half finish was cancelled out by Nathan Broadhead’s header but Óscar Estupiñán’s deflected goal and Smith’s late double secured back-to-back away victories.
Liam Rosenior kept faith with the same XI that defeated Birmingham City, with captain Lewie Coyle back among the substitutes after recovering from a foot problem.
The visitors were aiming to make it seven away games unbeaten against a struggling Latics side still searching for their first win under Kolo Toure, having lost their previous two matches 4-1.
Kicking towards the noisy 2,500 travelling contingent, City completely dominated a first 15 minutes spent camped inside the home half, enjoying 80% possession and posing a persistent set-piece threat.
From corners, Alfie Jones’ drive was blocked after intricate footwork from Regan Slater and Sean McLoughlin’s glancing near-post header was diverted wide by Estupiñán from close range.
It came as little surprise then when City opened the scoring from a corner Wigan failed to clear, Greaves guiding a composed first-time finish into the top corner with his trusty left foot.
The lowly Latics briefly came out of their shell as Max Power whipped a wide free-kick onto the top of the net and Ryan Nyambe’s 20-yard shot was charged down by Estupiñán.
The Tigers always looked in control throughout a one-sided opening period but were unable to extend the advantage, with Slater and Greg Docherty off target with speculative long-range strikes.
Allahyar Sayyadmanesh, making only his third appearance after a four-month injury lay-off, was forced off at half-time having twice gone down during the first half.
Smith came on in his place, while Toure made three changes within the first 10 minutes of the restart to reinvigorate his side.
Having scored from a corner, City were undone by one on 63 minutes as Wigan equalised from their first attempt on target, Broadhead heading in McClean’s inswinging delivery.
The momentum had shifted in Wigan’s favour but Rosenior responded by bringing on Ryan Woods and Ozan Tufan - and his side regained the lead with 12 minutes left.
Curtis Tilt inadvertently diverted Alfie Jones’ searching ball into the path of Estupiñán, whose scuffed left-footed shot took a deflection off Jack Whatmough, wrong-footed goalkeeper Jamie Jones and trickled into the net.
Already in full voice, the City faithful were in dreamland as McLoughlin’s long ball released Smith in behind and the forward rounded Jamie Jones before finishing with aplomb from a narrow angle.
A superb away day got even better in added time as Slater dispossessed Max Power, surged powerfully down the right and whipped in an inviting cross for Smith to tap home.
Wigan Athletic (4-2-3-1): J Jones; Nyambe, Whatmough, Tilt, Bennett (Magennis 75’); Power ©, Cousins (Naylor 55’); Lang (Broadhead 46’), Keane, McClean; Fletcher (Aasgaard 55’).
Subs not used: Amos, Edmonds-Green, Darikwa.
Hull City (4-3-3): Ingram; Christie (Figueiredo 83’), A Jones, McLoughlin, Greaves (C); Seri (Tufan 75’), Docherty, Slater; Longman (Woods 68’), Estupiñán (Coyle 83’), Allahyar (T Smith 46’).
Subs not used: Lo-Tutala, Elder.
Attendance: 12,522 (2,520 Hull City supporters).
